Apparatus for controlling grinder stones in pulp mills



Feb. 20, 1923.

C.-L. HENDERSON APPARATUS FOR CONTROLLING GRINDER STONES IN FULP MILLS 5sheets-sheet 1 Filed Dec. 3, 1921 NnN - Feb. 20, 1923. V

' C. L. HENDERSON APPARATUS FOR CONTROLLING GRINDER STONES IN PULP-MILLSwmkwk M v v N NM/ JL M Q I NM F. M {mm mN W N @N Q Q% N 3% NM 4 w KWI... .1. mwmw xv 5 MW u. mw QM; s

Feb. 20,1923.

I C. L- HENDERSON APPARATUS FOR CONTROLLING GRINDER STONES IN PULP MILLS5, 1921 5 sheets-sheet 5 Filed Dec WW M RP F P w Patented Feb. 20, 1923.

v u'ire rs 'ATENT OFFI E;

CHARLES L. HENnERsomor APPLETON, WIscoNsIN, AssiGNon 'ro KIMBERLY-CLARKCOMPANY, or NEENAH, WISCONSIN, A CORPORATION or Wisconsin.

APPAnATUsron CONTROLLING GBINDERSTONES IN PULP MILLS.

Application filed December 3, 1921. vSerial N0. 519,737.

To all whom it may concern:

Be it known that I, CHAnLus L. HENDER- soN, a citizen of the UnitedStates, residing at Appleton, in the county of -Outagamie and State ofWisconsin, have invented certain new and useful IHIPIOYQIIIQHtS inApparatus for Controlling Grinder Stones in Pulp Mills, of which thefollowing is a specification.

lVIy invention relates to improvements in method and apparatus forcontrolling grinder stonos'in pulp mills, and has special value inconnection with grinder stones which are driven by motors having sub-.stantially uniform ample, watervwheel y In this country, in View of thefact that pulp mills require large quantities of. water,

they are generally located at such points that there are available, notonly the required supply of water, but also va. suiiioient head of waterto operate certain portions "of the mill apparatus which requireconsiderable quantities of mechanicalpower. Generally such water poweris employed for driving the grinder stones which are used for producingthe ground wood or mechanical pulp required for use in the mill. TheWater wheels or turbines which are connectedv to the stones are notordinarily equipped with speed governors for-a numberof reasons. :In thefirst place, the governing ofthe speed of the water wheel or turbine,which consumes a large quantityof water, is attended with considerablemechanical difiiculty and very often with waste of water. Also theequipment :necessary for such governing is relatively expensive. both infirst cost and vto operateand maintain in efficient working order; also,

owing to the fact that the water power available must usually beutilized to the utmost in order to conserve power cost, it is desirableto be able to operate the grinder stones at full load and at maximumeliiciency continuously. over extended periods.

In any case, whatever thereasons may be, 1

in this country, it has not been the custom to equip with governors, thewater wheels or turbines used for driv ng grinder-stones.

The absence of governmg mechanism for the grinder stones, on the otherhand, results in undesirable conditions. In the --first place, when thesupply of wood in the pock-,

ets of the stone become exhausted, the load power capacity, for ex--vented from rising above or below certain prescribed limits founddesirable for the on the stone is correspondingly reduced, resulting ina considerable increase in speed. Such increase in speed is a point ofdanger in the operationof the grind-er stones which frequently explodeby reason of the exces sive speed, o fitenvcausing serious propertydamage and sometimes loss of life. Furthermore, and of still moreimportance, from a practical standpoint, the excessive speed of thestone has a deleterious effect upon the ,pulp produced, since it isfound that pulp, to be of the highest quality, must be produced withincertain ranges of pressure andspeed. i

.iV'th theabove conditions in mind, it will be understood thatthepnincipal objects of my invention are, to provide a method andapparatus of controlling grinder stones whereby the speed of-the-stonemay be pre most successful operation, to provide a system of operatinggrinder stones whereby the power consumption may be maintainedsubstantially constant and whereby the cili ciency, of the motive powermay-be maintained at a maximum; :to provide a system and arrangement ofthe classdescribed so organi ed-thatthe production of pulp and thequality thereofis -the highest ,possible;,; to provide an apparatus forthe purpose described which may be manufactured and installeda-tininimum expense and which may be operated-and maintainedinexpensively and efficiently, and ingeneral, to-yprovide a. rugged,reliable. and eflicient apparatus of' the characterreferred to. In thedrawings which illustrate my in- VGDtzlOll as applied to a grinder stonedriven by a water wheel or atu rbine,

Fig.. 1 isia plan view. of the complete apparatus, certain parts beingshown-on an v exaggerated scale iii order to rendermthe drawing morelegible;

swi 1;: V i I ,Fig, 5V is a section taken on the 1ine-3 -3 ofFig.2;- V iFig. is a section taken on'the l ne 4-7-4 o-f,Fig.2;, I v Fig.5isasection1taken on the line 5-5 of Fig.2; V, I t Fig. 6 is a sectiontaken on the ,lineyfi-G ns-5;

Fig. '7 is a section similar to Fig. 6, but

Fi .2 islasection taken on the lineQ -Q v showing the controlling valvein a different position; and

Fig. 8 is a section more or less diagram.- matic showing the grinderstone and water wheel in elevation.

Referring to the drawings, 10 represents somewhat diagrammaticallythewater turbine which operates the shaft 11 on which the grinder stone12 is mounted in the usual pipe 21 common to the three pressurecylinneed have no connection with the main water ders. Water underpressure is supplied to the pipe 21 from a suitable sourk-e, such as apump, preferably equipped with a pressure reservoir whereby the waterpressure may be maintained at a substantially constant figure. It willbe understood that the water used for supplying pressure in the pocketssupply which operates the turbine 10. The

' governlng element comprises a controlling valve contained within acasing 22 interposed at a convenient point in the run of the pressuresupply pipe 21. As indicated best in Figs. 2, 4, 5, 6 and 7, said valvecomprises a cylindrical body portion 23 rigidly mounted on a frameintegral with an operatlng stem 24 extending through a boss 25 and. oneSldB of the valve'casing. The body of the valve 23 is slotted orapertured as shown at 26, the ends of said slot registering with ports2( and 28 formed in the casing and communicating with the pipe 21, theport 27 belng thus in free communication with the pump or otherpressure-water source, while the port 28 is connected directly with the.

pocket cylinders. By reference to Figs. 2, 5, 6 and 7, 1t will beobserved that there is formed in the .valve casing 22, a longitudinallyextending duct 29 which communicates y or sewer.

with the port or passage 28 and also with a narrow port slot 30 in theextended end of the casing. Said slot 30 is adapted, on occasion toregister with acooperating slot 3]. formed radially in the body of valve23 and communicating with a centrally longitudinally extending recess orpassage 82 the outer end of which communicates freely with an apertureor plpe' 33, connected tovwaste The purpose of said auxiliary or bleedport 30 is to relieve the pressure in the pockets without delay wheneverthe grinder stone slows down from any cause.

The controlling valve above described is operated automatically, and inaccordance with changes in the speed of the stone, by means of themechanism now to be described.

Such mechanism is mounted upon a. suitable base casting 34 which alsoserves as a support for the valve housing 22. At the end of said casingthere is journaled in a suitable bracket or pedestal 35 a transverseshaft 36, which shaft 36 is driven-by pulley 37 keyed thereon. Saidpulley 87 is connected by means of a belt 38 to asimilar pulley 39 keyedon the shaft 11 of the grinder stone. Hence, said transverse shaft 36will rotate at the same speed as grinder stone shaft 11.

Located adjacent to the pedestal 35, having its bearing axis at rightangles thereto, I mount on saidbase 34, a second pedestal 40, withinwhich is journaled a sleeve 41,-

said sleeve serving as a bearing for shaft. 42,

On the outer end of said shaft 42 there is keyed a bevel gear 43 whichmeshes with a bevel pinion 44 keyed to the adjacent end of transverseshaft 36. Bevel gear 43 has twice the number of teeth as bevel pinion44, therefore shaft 42 will rotate at one-half the speed of the grinderstone shaft. Aligned with pedestal 40 is a short pedestal 45, saidpedestal serving as a journal bearing for a sleeve 46, similar to sleeve41'. Said sleeves 41 and 46 are provided with radially extending flanges47 and 48 spaced apart to admit a drumor pulley 49. Said flanges 47 and48 are rigidly secured to the sides of said pulley 49 so that sleeves 41and 46 will be thereby rigidly connected together i and revolve as aunit. The sleeve 46 serves as a journal bearing for ashaft 50 with whichthe valvestem 24 is aligned. and. to which said sleeve stem 24 isrigidly con-' nected, by means of a suitable coupling 51. suitably boredout to receive the adjacent ends of shaft 50 and stem 24."

' The coupling may be. if desired, equipped with suitable keys as at .52and is preferably provided with. a pair of clamping bolts 53 for thepurpose of locking said valve stem 24 and shaft 50. said stem 24 thusbeing in effect an integral extension of shaft 50 To the adjacentopposed ends of shafts42 and 50 there are keyed, respectively, two

similar opposed bevel pinions 54 and 55, v said pinions being suitablyspaced to mesh with one or more planetary differential bevel gears 56carried by stub shafts 57 mounted in drum 49, saidstub shafts57 being.dis-.

posed with their axes extending radially from the center of drum 49which is, concentrio with the axes of shafts 42 and 50.

The drum 49 is turned off at its outer pe- I lriphery to accommodate afiat belt which belt 58 drives said -59 keyed to shaft 60, said shaft 60being pulley 49 from a pulley mounted to rotate in suitable la'eai'ings'T61 and '62 and is driven at a uniform speed and continuously by asuitable motive power such as an electric motor 63. A train of gearingcomprising pinion 64, spur gear '65,

shaft 66, pinion 67 and spur gear 68 serves to reduce the speed of saidshaftGOso that the pulley 49 will be driven at on'ehal-f the normal:speed of shaft 42, that is to say, at one-fourth-o'f the speed of thegrinder stone shaft. Preferably, inorder to maintain at all timessatisfactory #driyin'g tension on the belt 58, while permittingacer'tain amount of slippage incidental to the successful opera tion ofthe apparatus, I employ a rider or jockey pulley 69 resting on the topstretch of belt 58, and located in position by arms 70, having theirends 71 pivoted on the ends of pedestals and '45.

The operation'of the apparatus is as follows:

The grinder stone l2 revolves in the direction of arrow '72, and hencedrives pulley 37' in the direction of arrow 73 (see Fig. 2)., Thisresults in a rotary movement of shaft 42 in the direction of arrow 74.If the drum 49 were stationary and bevel pinions 56 fixed I as to theiraxes, the rotary movement of shaft 42 in direction of arrow 74 wouldresult in a reverse rotary movement of shaft in the direction of arrow75. Hence, in the absence of rotation of drum 49, shaft 50 will tend torotate in the direction of arrow 75, so as to rock the valve stem 24 andvalve 23 in the direction of arrow 76 (see Fig. 6).

Such rotation of valve 23 is, however, arrested when the valve is fullyopen, as in Fig. 6, by means of-a. stop arm 77 integral with coupling 51and the end of which ongages an adjustable stop screw 78.

Thus, if the drum 49 were stationary, rotation of the grinder stonewould result in the controlling valve being rocked into the positionshown in Figs. 4 and 6, and the full pressure of the pump would becommunic'ated to the cylinders of the grinder pockets, thereby forcingthe wood against the surface of the grinder stone with maximum pressure.However, in view of the fact that the drum 49 is not stationary, but mayrevolve on its sleeves 41 and 46 in pedestals 40 and 45, said drum willrotate at an aver age speed equal to half the speed of the shaft 42, orone-fourth of the speed of the grinder stone shaft. Such rotation of thedrum 49 will be in the direction of arrow 79 which is the same directionas the direction of rotary movement of drum 49 under the influence ofbelt 58 (see arrow 80). Thus, if motor 68 and grinder stone shaft 11 areexactly synchronized, there will be no tendency to rotate shaft 50, andhence the controlling valve 23 will not be actuated in either direction.practice, it is found that the con trolling valve 23 oscillates slightlycontinuously due to slight variations in speed of grinder stone shaft11. .lVhen' grinder stone shaft 11 races or tends to rise in speed,

the controlling valve will tend to rock into theposition shown in Fig.6, thus admitting more pressure water from the pump to the be completelyclosed by reason of the closing of the main valve opening 26 in additionto which, if ordinary leakage of thepistons does not sufficiently reducethe pressure of the stone and allow-its speed toenormalize, the valve 23'willbe I rocked still further toward the stop 81, thereby opening bleedport 31 which will effectively rob the pocket cylinders ofpressure.

The described details of construction and operation are merelyillustrative of a single phase of my invention, the scope of'whichshould be determined by reference to the appended claims, said claimsbeing con- When in such sub-normal position as shown in Fig. 7, thecommunication between t the pump and the pressure cylinders will struedas broadly as possible, consistent with o the state of the art.

I claim as my invention: a 1. In apparatus for controlling grinderstones used for making mechanical pulpfor paper mills, the combinationof a source ofr power, a grinder stone i coupled. to said source, apocket for holdlng wood which s being ground, means for pressing saidwood against the stone and means controlled by the speed of the stonefor varying said pressure, said last named means comprisingdifferentially connected elements, one "of which is driven atsubstantially constant speed and the other at a speed bearing a,

fixed ratio to the stone speed; a

2. Apparatus for controlling a grinder stone used for making mechanicalpulp for paper mills, comprising in combination a source of power, meansoperated by said power for .varymg the, load on sald stone, a constantspeed element and a member differentially acted uponby said": constantspeed element and by said grinder stone for automatically controllingsaid load controlling means in accordanceflwith change of grinder stonespeed. 7

3. In-combination, a grinder stone, pressure actuated means for applyingload to said stone, 'a valve for controlling said pressure and meanswhereby said Valve will be actuated automatically to, supply pressurewhen the grinder stone speed rises and to reduce the pressure when thegrinder stone speed falls, the arrangement including auxiliary means forreducing pressure when the valve is closed.

4. In a device of the class described, the (combination of a rotaryvalve for controlling fluid pressure, ashatt for actuating said valve, apinion on said shaft,,a shaft driven by the grinder stone, a gear onsaid last named shaft, a planetary gear meshing with said first twogears, and a'rotary support tor said last named gearoperated at constantspeed.

5,111 combination, a grinder stone, a

pocket cylinder, a source of fluid pressure, a valve "for controllingsaid pressure, a shaft for actuating said valve a bevel gear on saidshaft, a bevel gear axially aligned with said first named gear anddriven by the stone, a rotary support axially aligned with said shaft, aplanetary diiferential bevel gear mounted on said sup} )or't to meshwith both of said gears and means for driving said support in the properdirection at constant speed whereby said valve will be substantiallyunacted upon by said shaft when the grinder stone gear is driven attwice the speed of the support.

CHARLES L. HENDERSON.

